Effect of tetramethylpyrazine on reversing multidrug resistance of K562/MDR cells with gene transfer / 吉林大学学报(医学版)

ABSTRACT

Objective To investigate the reversal effects of tetramethylpyrazine(TMP) and cyclosporin A(CsA) on multidrug resistance(MDR) of human erythroleukemia cells with gene transfer K562/MDR and to discuss the possible correlative mechanism.Methods K562/MDR cells in culture medium were treated with TMP(50—6 400 mg?L-1) and CsA(0.5—256 mg?L1) respectively.The growth rates of these cells were measured by MTT assay.Non-cytotoxic doses of TMP and CsA were determined.There were 5 growps in the experimentG1(TMP+ADM+K562/MDR),G2(CsA+ADM+K562/MDR),G3(TMP+CsA+ADM+K562/MDR),negative control(K562/MDR subsitituted by K562/S),control(drugs subsitituted by 1640 culture medium),the inhibitory effects of adriamycin(ADM) used alone or in combination with TMP or/and CsA on the proliferation of K562/S and K562/MDR cells were observed by resisting fold and reversal folds.The effects of TMP and CsA on ADM accumulation in K562/S and K562/MDR cells were analyzed by fluorospectrophotometry.The protein level of P-glycoprotein(P-gp) was detected by flow cytometry(FCM).Results The non-cytotoxic doses of TMP and CsA were 320 and 2.0 mg?L-1,respectively.The resistance of K562/MDR cells to ADM was 19.2 folds of that of K562/S cells.When TMP and CsA were added along with ADM to the K562/MDR culture,the reversal folds were 5.2 and 9.6.When TMP in combination with CsA was added along with ADM to the K562/MDR culture,the reversal folds were 15.6.When various concentrations ADM were added to the K562/MDR culture,TMP and CsA could increase the intracellular accumulation of ADM.The effect of TMP in combination with CsA was more evident.Compared with control,TMP and CsA could inhibit the overexpression of P-gp protein(P